Multiple-drill holder.



G. P. TAYLOR.

MULTIPLE DRILL HOLDER.

APPLICATION FILED MAR. 21, 1011.

1,074,025. Patented Sept. 23, 1913.

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G. P. TAYLOR.

MULTIPLE DRILL HOLDER.

APPLICATION FILED MAR. 21, 1011.

1,074,025. Patented Sept. 23,1913.

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t I E ENT EPIC.

MULTIPLE-DRILL HOLDER.

To all whom, it may concern:

Be it known that I, GEORGE P. TAYLOR, a citizen of the United States, residing at Clinton, in the county of lVorcester and State of Massachusetts, have invented a new and useful Multiple'Drill Holder, of which the following is a specification.

This invention relates to an attachment for drills capable of supporting a plurality of drills in convenient position so that any one of the drills can be brought into operative position in a very simple manner without dismounting or replacing the individual drills.

The principal objects of the invention are to provide a construction of this character in which a holder is arranged with a central spindle connecting with the power and a plurality of holders each ar anged around it, each capable of supporting a drill in inoperative position and each adapted to be entirely unconnected with the power when the drill therein is not in operative position; to provide a construction in which the drills not in use are not rotated by the rotating central spindle; to provide a construction in which when any drill is in position for operation the other drills cannot be moved into contact with it or with its holder; to provide a construction in which when a drill is moved into operative position it is selfcentered and frictionally clutched to the central rotating spindle; to provide av construction in which the drills can be changed without stopping the machine and even without disconnecting the operating drill from the power except by moving it away to inoperative position; to provide a construction in which each holder is automatically locked in inoperative position when moved thereto and automatically locked in operating position when moved thereto; to provide a construction for readily introducing and removing the collets so that those of different sizes can be substituted very readily; and to provide various improvements in details of construction as will appear hereinafter.

Reference is to be had to the accompanying drawing in which Figure 1 is a side view of a small upright drill showing one form of this invention applied thereto. Fig. 2 is a plan of the attachinent. Fig. 3 is a sectional view thereof on the line 33 of Fig. 2. Fig. i is a central sectional view of the central spindle, and

Specification of Letters Patent.

Application filed March 21, 1911.

Patented Sept. 23, 1913.

Serial No. 615,900.

Figs. 5 and (3 are side and end views, respectively, of the locking device.

The invention is shown in a form in which a main frame 10 is provided having a removable arm 11 thereon extending 1': dially from it and provided with a guide plate 12 embracing the adjacent member of the frame A of the drill on which it is mounted. This arrangement is provided so that while the frame 10 can move up and down, it cannot rotate on or with the spindle. The frame has a plurality of sockets 13 into which this arm can be inserted so that the frame can be located in different angular positions.

The frame 10 is provided with a central passage therethrough in which is located a vertical central driving spindle 15 fitting in a socket in the driving spindle A of the upright drill or other machine on which it is placed. This spindle goes into position in the same way as the ordinary drill shank. This spindle 15 is provided at its outer end with an enlargement 16 forming a shoulder. ()n this shoulder preferably are located a series of bearing balls 17 which engage an inner shoulder 18 on the holder 10 and pro vide the necessary bearing. Also at the bottom this spindle is provided with a conical clutch surface 19 and a pin 20 projecting outwardly at one side of the center. At the center it is counter-bored at 21.

Arranged around the frame 10 are a plurality of transverse pivot pins 22, on each of which is pivoted a swinging arm or holder 23. Each of these holders is provided with a passage thercthrough in which is adapted to be supported a collet 25 or 26. Each collet is provided with a groove 27 of substantially semi-circular form in cross section and each arm is provided with a spring-pressed ball plunger 28 held in by a screw 29 for engaging in said groove and holding the collet in position. By this means the collet can be very easily inserted and removed without the expenditure of any appreciable amount of time.

Each of the collets 25 is provided with a shoulder 30 and near it with a conical edge 31 adapted to fit the conical friction clutch surface 19 on the end of the central spindle. The end of the collet has a groove 82 across the same and. as is usually the case, the collet is provided with a central passage for receiving the tang of a drill. In this case this central passage is so sized that the tang of the drill will project beyond the flat end of the collet when the drill is inserted in the collet ready for operation. For this reason the drill can be very easily removed from the collet by striking thesame with a mallet or taking it up and striking any flat surface with the projecting tang.

Each collet 26 is solid instead of hollow, and has a non-circular projection 33 on the end, on which a clutch 34 is adapted to be driven. This is for holding small drills. All the collets may be of either kind or part of each,

Each of the-arms 23 is held in position by a spring plate 35 mounted on the frame 10 and provided with a perforation 36 for receiving the round head of a screw 37 on the arm. On the side of the frame l0vis a spring-pressed lever 38 having a locking pin 39 operating in guide 40 and on each of the arms is a cavity 41 for receiving this locking pin when the arm is swung into operative position.

The operation of this device is as follows: Starting with the device in a position in which all the drills mounted in the several collets and all the collet supporting arms are raised to a position substantially parallel with the central spindle, it will be understood that they are locked in position by the spring plate and screws 35 and 37.

' Now assuming that the machine is in operation and the central spindle rotating, when it is desired to use any one of the drills the operator simply takes hold of the drill or its holder and swings it out on its pivot in opposition to the spring-plate 35. (See dotted lines in Fig. It swings clear around and the conical surface 45 engages the beveled end of. the locking pin, and forces it out so as to permit the arms to swing into position so that the two conical surfaces 19 and 31 come into contact. Then the locking pin automatically moves into the socket and looks it in position. This results in centering the collet,;and frictionally clutching it to the central spindle. If it slips, however, the pin 20 positively connects it therewith. The conical edge 45 of the arm 23 also engages the conical socket 46 of the frame,10, and this centers the arm 23. The locking pin 39 will automatically slip into position to lock the holder in this position and the operator can drill the hole in the usual way as the collet and drill held thereby now rotate positively and concentrically with the central spindle. It

will be s'eenthat the conical edge 45 of the pivoted arm 23 that is in place for drilling engages not only with the conical cavity 46 but also the inclined inner ends 47 of the other pivoted arms 23. These are beveled off to coincide with the conical form of this cavity. It will be impossible therefore to swing any one of the other holders down out of its place, and any attempt to swing them out of place will not cause any pressure to be exerted on the drill or collet that are being used, and cannot possibly result in any harm to the apparatus or work on which it is being used.

In order to change drills it will be necessary to operate the locking lever 38 to withdraw the locking pin 39which allows the drill holding arm 23 to swing out by gravity when the device is being used on an upright drill. Then it can be swung up by hand into its upright position and another drill substituted simply by swinging it into proper position. In case the second drill is lowered after the first swings down, but

before it is entirely out of the way, the locking pin ordinarily will prevent its coming into such position as to operate, but if that is withdrawn it will force the first drill holder back out ofthe way without damaging the same.

The work can go on with no appreciable pause and the first drill can beremoved .to upright position at the leisure of the operator. In this way it will be seen that a piece of work requiring any conveinient number of drilling operations by different drills can be operated upon with a loss of an extremely small amount of time between drilling operations. The drills do not have to be removed or reset in the collets and I they are always in convenient position for being brought into operative condition and are entirely inoperative when out ofposition for drilling.

While I have illustrated and described a preferred embodiment of the invention, I am aware that many modifications can be made therein by any person skilled'in the art without departing from the scope ofthe invention as expressed in the claims. Therefore, I do not wish to be'limited' to all the details of construction herein shown and described, but

l/Vhat I do claim is 1. In a device of the character described,

the combination with a spindle, of a plurality 'of drill holders arranged around the same and pivoted on axes transverse to the axis of the spindle, each one being adapted to swing on its pivot into a position in which a drill or the like carried thereby, will be in alinement with the spindle, each of said holders having a surface adapted to engage a drill holder in operative position for preventing the inoperative holder from being turned toward operative position while one i of the other holders is in operative position.

2. In a device of the character described, the combination with a central spindle, of a frame supported thereby, a plurality of auxiliary drill holders movably mounted on said frame around said spindle, collets on said holders, each constructed and adapted to be moved into position in which it will come into frictional contact with the end of said central spindle, each of said auxiliary holders having means for preventing its being turned on its aXis in any direction while one of the other auxiliary holders is in operative position, said means being ar' ranged and adapted to engage such other auxiliary holder when the latter is in operative position.

3. In a device of the character described, the combination of a central spindle having a surface at the end, a collet for holding a drill having a surface adapted to engage and fit the surface at the end of the spindle and having a passage for the reception of drill shanks of such size as to permit the tang of the drill to project beyond the end of the collet, and means for movably supporting said collet at the side of said spindle, said means being movable to two positions, in one of which said surface 011 the collet engages said surface on the end of the spindle, and in the other of which said surface on the collet is at the bottom of said means and both ends of the collet are exposed, said means having a readily detachable element for normally holding the eollet therein and pern'iitting it to turn.

In testimony whereof I have hereunto set my hand, in the presence of two subscribing witnesses.

GEORGE P. TAYLOR.

\Vitnesses C. Fonnnsir lvrzssoiv, E. M. ALLEN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, I). C. 

